Wearable scanning photoacoustic brain imaging in behaving rats

A wearable scanning photoacoustic imaging (wPAI) system is presented for noninvasive brain study in behaving rats. This miniaturized wPAI system consists of four pico linear servos and a single transducer-based PAI probe. It has a dimension of 50 mm × 35 mm × 40 mm, and a weight of 26 g excluding cablings. Phantom evaluation shows that wPAI achieves a lateral resolution of ∼0.5 mm and an axial resolution of ∼0.1 mm at a depth of up to 11 mm. Its imaging ability is also tested in a behaving rat, and the results indicate that wPAI is able to image blood vessels at a depth of up to 5 mm with intact scalp and skull. With its noninvasive, deep penetration, and functional imaging ability in behaving animals, wPAI can be used for behavior, cognition, and preclinical brain disease studies.